05/24/2023 Notes Flashcards
What is a tendon?
A connective tissue layer that forms at the end of a muscle and attaches to the bone
What is an aponeurosis?
A thin, flattened sheet of tendon
What is the origin of a muscle?
The less movable attachment that tends to be proximal to the insertion
What in the insertion of a muscle?
More movable attachment that tends to be distal of a muscle
What do blood vessels do in the muscle?
Deliver nutrients and oxygen needed for ATP production and removes waste
Skeletal muscles are involuntary or voluntary?
Voluntary
What part of the nervous system controls skeletal muscles?
Somatic nervous system
What do efferent neurons (motor neurons) do?
Stimulate muscle contraction and innervate muscle fibers
What do afferent neurons (sensory neurons) do?
Send impulses to the brain and spinal cord about activity of muscles
What do axons do?
Transmit a nerve impulse to muscle fiber
What is atrophy?
Wasting away of muscle fibers when they are not used
What are fascicles?
Bundles of muscle fibers
How are circular muscles arranged?
Concentrically around an opening or recess
What are examples of circular muscles?
Sphincters, such as the orbicularis oris
How are parallel muscles arranged?
Fascicles run parallel to its long axis
Parallel muscles have a central body, also referred to as…?
Belly
What are examples of parallel muscles?
Biceps brachii and rectus abdominis
How are convergent muscles organized?
Widespread muscles that converge on a common attachment site that often resemble a broad fan (triangular shaped)
What is an example of a convergent muscle?
Pectoralis Major
What are pennate muscles?
Muscles that resemble a feather
What are the three types of pennate muscles?
Unipennate, bipennate, and multipennate muscles
What is a lever?
An elongated, rigid object that rotates around a fulcrum (fixed point)
What is the effort arm of a lever?
The part of a lever form the point of the fulcrum to the point of effort
What is the resistance arm of a lever?
Part of the lever from the fulcrum to the point of resistance
The long bone acts as a lever that moves what?
Resistance (R)
The joint acts as the what?
Fulcrum (F)
What is generated by muscles in a lever system?
Effort (E)
What is a first class lever system?
The fulcrum is in the middle of the effort and resistance and the movement is similar to a seesaw
What are examples of first class lever systems?
Atlanto-occipital joint and triceps brachii
What is a second class lever system?
The resistance is between the fulcrum and effort and the movement is similar to lifting a wheelbarrow
What is an example of a second class lever system?
Contraction of calf muscles to stand on tiptoes
What is a third class lever system?
The effort is between the resistance and fulcrum, and the movement is similar to a drawbridge
What is the most common lever system in the body?
Third class lever system
What are examples of a third class lever system?
Flexion of elbow, elevation of mandible
What is an agonist muscle?
The prime mover that contracts to produce a particular movement
What is an antagonist muscle?
Muscle that opposes agonist muscle; allows for control over the speed of agonist muscle for smooth movements
What is a synergist muscle?
Muscle that assists the agonist
What are some criteria that skeletal muscles are named after?
Muscle action, specific body region, muscle attachments, orientation of muscle fibers, muscle shape and size, muscle heads and tendons of origin, and relative position
When does slow, progressive muscle loss start to occur?
In a person’s mid-30s
What are some effects that aging has on muscles?
Reduction in contractile filaments which leads to atrophy, tolerance for exercise decreases, rapid fatigue, reduced capacity to recover from disease and injury, and decrease in muscle elasticity due to fibrosis
How can aging effects on muscles be reduced?
Proper moderate exercise and good nutriton
What are some functions of axial muscles?
Support and move the head and vertebral column
Function in nonverbal communication by affecting facial features
Move lower jaw during mastication
Aid in breathing
Support and protect abdominal and pelvic organs
Where are the origins and insertions of axial muscles located?
On the axial skeleton
What 4 muscles are involved with facial expression?
Occipitofrontalis, orbicularis oris, platysma, and buccinator
What is mastication?
Process of chewing accomplished by muscles that move the mandible at the TMJ
What three muscles are involved with mastication?
Temporalis, masseter, and Pterygoid
What is tetanus?
A toxigenic would that occurs following a dirty puncture would and results in tetany (involuntary muscle contraction) that usually affects the mandible first; “lockjaw”
